| 摘要 |
PURPOSE:To contrive an improvement in heat resistance and strength in a longitudinal direction of a heat-sensitive transferring film by manufacturing and making use of a biaxially oriented film having polyethylene-2, 6-naphthalate, whose Young's modulus in the longitudinal direction is more than a specific value, for its main ingredient. CONSTITUTION:A substantially nonorientated and unstretched sheet is manufactured by fusing and extruding polyethylene-2, 6-naphthalate polymer raw materials which has made to contain, for example, fine particulates such as kaolin or silica at 280-320 deg.C and quenching and curing the same and the sheet is stretched at magnification of more than 1.1 times and less than 3.5 times so that an index DELTAn of birefrigence in a longitudinal direction becomes less than 0.080 at the temperatures of 130 deg.C-170 deg.C. Then the same is stretched laterally at more than 2.5 times and less than 4.0 times as wide as the same at the temperatures of 130-180 deg.C and the same is heat-treated while the same is being slackened 1-30% in a widthward direction at 130-240 deg.C. When the biaxially oriented film is fixed thermally while the same is being stretched longitudinally at more than 1.1 times and less than 4.0 times as long as the same and stretched laterally at 1.01-1.5 times as wide as the same, a film whose longitudinal modulus and traverse modulus are as high as more than 600kg/mm<2> exceptionally is manufactured. |
